http://www.zeroknowledge.com/company/pressrel.asp?rel=07091999
described defcon7, as follows:

DefCon 7--Las Vegas, NV--July 9, 1999
...
DefCon 7, the computer industry's most eccentric annual conference.
DefCon is an annual gathering in Las Vegas of computer enthusiasts,
cryptographers, futurists, privacy advocates and technology elite that
previews upcoming developments in privacy, computer security and technology.
"This conference is the Woodstock of the computer industry, an annual
gathering of technology elite in the real sense of the word 'hacker.'
This community will be our technology's strongest critics until they
try it--and, over time, we believe they will become its greatest
supporters," said Austin Hill, president of Zero-Knowledge Systems.